AIO, I’m 16M and my Mom threatened to kill/hurt herself and said that she was suicidal, idk what to do and I need help

Im going to explain exactly what happened:

Context:

Basically this started over a really petty argument. My Mom was gone for a business trip and me and my brother had someone who came to pick us up and take us to school, the person came to our house at 8 am, and we had to get ready exactly at 8 so the person wouldn’t be late for their job after they dropped us to school. Me and my brother got ready at 8 everyday and everything was fine. When my mom came back from her business trip two days ago our schedule resumed as normal. Today, I got late because I was trying to find something I had to take to school, I ended up getting us “late” and we left at 8:05. My mom got really angry. She said when she was on her business trip we got ready at 8 exactly, but when she got back, we didn’t respect her and get ready at 8 like we did for the other person. Keep in mind we already got into a big yelling match the day before due to another petty argument so we were both already mad at each other.
The argument ends up with us going back and forth and then she starts yelling at me, like really, really loudly in the car, to the point that it pierces your ears. At this point I‘m already crying and I have tears everywhere, shes still driving me to school and I start begging her to take me home because my eyes are super bloodshot and I cant stop crying, I thought she would take me home but instead she keeps driving me to my school, when we are about 2 minutes away, and I can see kids with backpacks and students walking to school I start frantically begging her. She starts “hyperventilating“ and starts saying “I’m going to commit suicide” “I’m suicidal“ ”please” as we get closer to the school. Eventually we are parked directly in front of the school, and I’m still begging her to take me home and then she starts screaming at me again, telling me to “get out of her car” or she is going to “do something” and she is going to “hurt herself”. With tears in my eyes I eventually just get out of the car because I don’t know what to do and I have never seen her like this, or say this. (It’s worth noting that my parents are extremely adamant about me missing school, and they make sure it doesn’t happen unless I’m extremely sick)

Aftermath:

Rigth after this happens I go straight to the park a minute away from my school while calling my uncle, who is normally extremely helpful in situations like this. He tells me to calm down and he was going to call my mom, who was driving away from the school. He calls my mom and about five minutes later he calls me back. He tells me that she “seemed calm” when he was on the phone with her and then he asks me where I was. I told him I was the park and I wasn’t going to school because I was still crying and I had no clue what just happened and I was scared and confused. He then told me that I should “just forget“ everything and go to school. I was extremely shocked because this was the last thing I expected to say. I told him i couldn’t and then he just said “sometimes you have to be strong” and I needed to “forget about it” and I HAD to go to school otherwise “I was going to make this ten times worse and everything was going to escalate“. After going back and forth for another five minutes he saw I wasn’t going to go to school and he said “your choosing not to take my advice” and “I dont know how to help you”, and then finally saying “I should call my dad”. I was actually in shock and I proceeded to call my dad. When my dad picked up I pleaded him to please come pick me up and he said he would. About fifteen minutes later I called him again and asked if he was almost here and he said that he was “too sleepy” and he couldn’t drive right now and he said he could come in two hours. I was confused why nobody was taking me seriously and after thinking for ten minutes I called 911. I told them exactly what happened and they asked me if I knew where my mom was and if she was ok. The guy then told me he was transferring me to a line that could help me. After waiting for fifteen minutes I was shocked when the person who answered the line was the person i just talked to. He said that he could send a police officer if I wanted or I could just wait for my Dad to pick me up. I ended up sitting in the park freezing my ass off for 2 hours until my dad got ready, made coffee, and picked me up, and drove me back without saying a single word.

It’s been about six hours since when I’m writing this post, I don’t know what to do, my mom came back and she has been in her room and everyone in my house is acting like nothing happened. Am I the one overreacting here? Do I need to call someone or some protective service? What do I do I’m lost and I really need help.

So sorry for the huge block of text